FILED

United States Court of Appeals

Tenth Circuit

February 8, 2010

Elisabeth A. Shumaker

Clerk of Court

PUBLISH

UNITED STATES COURT OF APPEALS

TENTH CIRCUIT

TERRI CRANDALL; JOANN

HUBBARD,

Plaintiffs - Appellants,

v. No. 08-1197

CITY AND COUNTY OF DENVER,

Colorado, d/b/a The Denver

International Airport, a Colorado

political subdivision,

Defendant - Appellee.

APPEAL FROM THE UNITED STATES DISTRICT COURT

FOR THE DISTRICT OF COLORADO

(D.C. NO. 1:05-CV-00242-MSK-MEH)

Frederick Ganz (John D. Fognani, Perry L. Glantz, and Fritz W. Ganz with him

on the briefs), Fognani & Faught, PLLC, Denver, Colorado, for Plaintiffs -

Appellants.

Andrew J. Carafelli (Chris Mattison and Peter Moyson with him on the brief),

Hall & Evans, L.L.C., Denver, Colorado, for Defendant - Appellee.

Before HARTZ, HOLLOWAY, and TYMKOVICH, Circuit Judges.

HARTZ, Circuit Judge.
1

This RCRA provision also governs waste that may present an imminent and

substantial endangerment to the environment, but Plaintiffs have not pursued a claim of

environmental endangerment.

-2-

Plaintiffs Terri Crandall and JoAnn Hubbard sued for injunctive relief

against the City and County of Denver under the citizen-suit provision of the

Resource Conservation and Recovery Act of 1976 (RCRA), 42 U.S.C.

§ 6972(a)(1)(B). Their concern is that aircraft deicing fluid (ADF), which can

produce hydrogen-sulfide gas when it decomposes, endangers human health at

Concourse B of the Denver International Airport. The gates on Concourse B are

used almost exclusively by United Airlines. Crandall is a United employee, and

Hubbard is a former employee who now frequently uses Concourse B as a

passenger. Plaintiffs seek (1) to prohibit full-plane deicing at Concourse B gates

and (2) to require other precautionary steps relating to ADF.

Following a five-day bench trial, the United States District Court for the

District of Colorado denied Plaintiffs relief. It found that Denver no longer

permits full-plane deicing at the gates and held that Plaintiffs had not shown that

the current use of ADF “may present an imminent and substantial endangerment

to health,” which is a prerequisite for RCRA relief. 42 U.S.C. § 6972(a)(1)(B).1

The court also held that RCRA does not govern all the ADF by Concourse B at

the Denver Airport, but only the ADF “that flows in storm water into [C]oncourse

B and degrades in Concourse B.” Crandall v. City and County of Denver,

Colorado, No. 05-00242 at *27 (D. Colo. 2008) (in Aplt. App., Vol. 1 beginning
-3-

at 40) (Bench Ruling). The ADF that degrades outside the concourse, it said, was

governed exclusively by permits issued under the Clean Water Act (CWA). 

On appeal Plaintiffs argue that the district court misconstrued RCRA’s

requirements with respect to injunctive relief. They also contend that the court

erred in holding that the CWA, rather than RCRA, governs some of the ADF at

the Denver Airport. We affirm the district court’s denial of injunctive relief. 

Plaintiffs failed to demonstrate that ADF at the airport (whether it degrades inside

or outside Concourse B) may present an imminent and substantial endangerment

to health. Because relief under RCRA would therefore not be available even if

RCRA governs the ADF that degrades outside the concourse, we need not address

whether such ADF is governed exclusively by the CWA. 

I. BACKGROUND

A. RCRA

 RCRA is a comprehensive statute designed to reduce or eliminate the

generation of hazardous waste and “to minimize the present and future threat to

human health and the environment” created by hazardous waste. 42 U.S.C.

§ 6902(b); see id. § 6902(a). To achieve this goal, the statute “empowers EPA to

regulate hazardous wastes from cradle to grave, in accordance with [RCRA’s]

rigorous safeguards and waste management procedures.” City of Chicago v.

Envtl. Def. Fund, 511 U.S. 328, 331 (1994). It also grants private citizens

standing to enforce some of the statute’s provisions. See 42 U.S.C. § 6972;
-4-

Meghrig v. KFC Western, Inc., 516 U.S. 479, 484 (1996). The RCRA citizen-suit

provision invoked by Plaintiffs states: 

[A]ny person may commence a civil action on his own behalf—

. . . .

[1](B) against any person, . . . including any past or present

generator, past or present transporter, or past or present owner or

operator of a treatment, storage, or disposal facility, who has

contributed or who is contributing to the past or present handling,

storage, treatment, transportation, or disposal of any solid or

hazardous waste which may present an imminent and substantial

endangerment to health or the environment[.]

42 U.S.C. § 6972(a) (emphasis added); see Burlington N. & Santa Fe Ry. Co. v.

Grant, 505 F.3d 1013, 1020 (10th Cir. 2007) (summarizing citizen-suit

provision).

B. ADF and the Denver Airport

Plaintiffs do not challenge the district court’s rendition of the historical

facts. We begin by discussing some pertinent science and then summarize the

history of ADF use at the Denver Airport and the problems that have and have not

arisen. 

1. The Risks of ADF

ADF is mostly propylene glycol. When propylene glycol degrades in an

anaerobic environment where sulfur is present, hydrogen-sulfide gas can be

produced. Hydrogen sulfide has a characteristically offensive odor, which often

accompanies sewage or rotten eggs. It can be smelled at very low concentrations
-5-

in the air. Some people can detect it at one part per billion, and almost all

recognize it at 300 parts per billion. Much higher levels, however, are required

before it has recognized health effects. “Eye irritation has been noted at between

5 and 30 parts per million—not billion”; “[m]arked eye and lung irritation occurs

at 200 parts per million”; and “[b]reathing impairment and unconsciousness

results at 1,000 parts per million.” Bench Ruling at 12.

2. Conditions Through Early 2006

After ADF is used to deice an airplane, hydrogen-sulfide gas can enter

Concourse B by two means. The ADF may degrade outside the concourse and the

resultant gas then infiltrates the concourse. Or the ADF may mix with storm

water and flow down through cracks in the tarmac. Because the concourse

basement extends under the tarmac, this mixture can leak into the basement where

the ADF degrades, producing hydrogen sulfide. 

Until practices at the Denver Airport changed in 2005, some planes could

be fully deiced with ADF while at their gates. Beginning in 1997, employees of

United Airlines and others who worked at Concourse B filed a number of

complaints about the rotten-egg smell and about health effects that are symptoms

of exposure to hydrogen sulfide. Some complaints linked the smell to degrading

ADF. Maintenance logs and reports also indicated the presence of hydrogen

sulfide in the basement, and one or two reports attributed the gas to ADF. A 1998
-6-

water-quality study made numerous recommendations to control the runoff of

ADF into the Denver Airport’s storm-water system. 

Perhaps the most significant episode occurred in 2001, when many people

complained of a foul odor and burning eyes in the Red Carpet Club in

Concourse B. Air testing detected concentrations of hydrogen sulfide above one

part per million. The Tri-County Health Department found that the gas flowed

from the basement level up to the Red Carpet Club through the elevator shafts. A

report by URS Corporation, a consultant retained by Denver, concluded that the

hydrogen sulfide came from degrading ADF. As a result, the elevator shafts next

to the club were sealed and measures were taken to prevent ADF from leaking

into the basement of Concourse B. Denver began a program (which was still in

effect at the time of trial) to seal cracks in the tarmac around the concourse, thus

preventing ADF from entering the ground.

Despite these measures, in September 2005 maintenance logs reported toxic

levels of hydrogen sulfide in a mechanical room in the basement of Concourse B

and stated that employees were advised not to enter the room without proper

safety equipment. Beginning about that time (the record does not provide a

precise date), Denver limited the amount of deicing that could be conducted at the

gates. Planes were directed to deicing pads away from the gates and the

concourse basement. Gate deicing was restricted to a few portions of the plane in

certain circumstances. (The district court found the evidence insufficient to
-7-

determine Denver’s motives for moving deicing from the gates—whether it was a

response to this lawsuit or more a matter of efficiency and economics.) In

addition, in 2006 Denver installed ventilation fans in two of the twelve basement

sump rooms and, as of trial, it anticipated installing fans in the remaining sump

rooms. 

3. Conditions After Early 2006

Even after full-plane deicing at the gates ceased at the Denver Airport,

there were some reports of the odor of hydrogen sulfide in the basement of

Concourse B. But the complaints were much fewer and not supported by

objective evidence. The Center for Toxicology and Environmental Health, an

independent engineering firm, conducted five air-quality tests between November

2005 and March 2008 at many sites in the concourse, but no hydrogen sulfide was

detected. The district court concluded that currently “the evidence does not

establish levels of either propylene glycol or hydrogen sulfide that are dangerous

to human health” in the basement of Concourse B. Id. at 34. 

A United Airlines official testified in April 2008 that United had no intent

to request full-plane gate deicing after this litigation ends. He said that there had

been discussions two years earlier about testing the use of glycol-recovery

vehicles at the gates, apparently to determine whether they could reduce the flow

of ADF into the environment after full-plane deicing. But United then decided

not to spend the money necessary to acquire the vehicles. An airport official
-8-

testified that Denver had no plans to allow United to return to full-plane deicing

at the gates. He explained that the airport had added deicing pads and that gate

deicing could create traffic congestion as inbound aircraft waited for gates where

deicing was taking place. He also said that gate deicing would require new

infrastructure to collect overspray and runoff. 

C. District-Court Proceedings

Plaintiffs filed their RCRA suit on February 7, 2005. They sought orders

requiring Denver to take various steps to protect people from hydrogen sulfide

produced by degradation of ADF, including a prohibition on full-plane deicing at

Concourse B gates.

After a five-day bench trial in April 2008, the district court entered

judgment for Denver, ruling that Plaintiffs had failed to demonstrate that ADF

may present an imminent and substantial endangerment at Concourse B. The

court found that the evidence at trial was insufficient to establish that under

current conditions at Concourse B the amounts of ADF were significant or that

hydrogen sulfide was present at levels dangerous to human health. The court also

determined that the evidence was too speculative to show a significant risk that

Denver would resume full-plane deicing at the gates. Although there was some

evidence that Plaintiffs’ lawsuit contributed to ending full-plane gate deicing, the

court noted that the decision was likely influenced by the following “economic

factors”: 
2

The parties’ briefs in this court dispute whether the district court erred in

deciding that the CWA, and not RCRA, governs deicing chemicals that degrade outside

Concourse B into hydrogen sulfide that enters Concourse B (leaving RCRA to govern

only deicing chemicals that enter the basement of Concourse B as liquids). But we

need not resolve this dispute. The district court made no findings regarding how much

hydrogen sulfide was covered by RCRA and how much was left to the CWA, but found

that even considering all sources of hydrogen sulfide, Plaintiffs had failed to

demonstrate that the gas may present an imminent and substantial endangerment to

health or the environment. Thus, the court’s fact findings and judgment were

independent of its view of the CWA.

-9-

the construction of new deicing pads away from Concourse B, greater

capability in using the pads to deice, the impact of pad deicing on the

speed and number of planes to be serviced, and a requirement of

precedent testing, presumably environmental testing, as to the effect

of deicing fluid, which United has been unwilling to perform. 

Id. at 42.

In addition, the district court said that Plaintiffs had not shown that

resuming full-plane deicing at the gates would pose a health risk. Denver was

continuing a program to seal the tarmac around Concourse B, had installed fans in

two of the twelve mechanical rooms in the basement in 2007, and had said that it

planned to install fans in the remaining mechanical rooms in the concourse. The

court noted that it was “without evidence to balance the effect of future full-gate

deicing against the effect of future fans.” Id.2

II. DISCUSSION

 “A party requesting a permanent injunction bears the burden of showing:

(1) actual success on the merits; (2) irreparable harm unless the injunction is

issued; (3) the threatened injury outweighs the harm that the injunction may cause
-10-

the opposing party; and (4) the injunction, if issued, will not adversely affect the

public interest.” Fisher v. Okla. Health Care Auth., 335 F.3d 1175, 1180 (10th

Cir. 2003). “[W]e review the district court’s grant or denial of a permanent

injunction for abuse of discretion,” SEC v. Pros Int’l, Inc., 994 F.2d 767, 769

(10th Cir. 1993), reviewing underlying questions of law de novo, see Att’y Gen.

of Okla. v. Tyson Foods, Inc., 565 F.3d 769, 776 (10th Cir. 2009). The

dispositive issue in this case is whether Plaintiffs have established the merits of

their claim, the first requirement for a permanent injunction. See Prairie Band

Potawatomi Nation v. Wagnon, 476 F.3d 818, 822 (10th Cir. 2007).

To prevail under RCRA’s citizen-suit provision, a plaintiff must prove that

a solid waste “may present an imminent and substantial endangerment to health or

the environment.” 42 U.S.C. § 6972(a)(1)(B). Plaintiffs contend that they proved

their health-endangerment claims but that the district court “erred in its

interpretation of the meaning of ‘imminent and substantial.’” Aplt. Br. at 17. 

Although they do not dispute that “the cessation of full aircraft gate deicing[]

resulted in at least a partial abatement of the conditions giving rise to the risk of

harm associated with the degradation of [ADF]”, Reply Br. at 9, they argue that

the possibility of resumption of such deicing presents an imminent and substantial

endangerment. They maintain that Denver halted full-plane deicing at the gates

because of this lawsuit, and they suggest that the practice likely will resume after

the lawsuit if no injunction is issued. According to Plaintiffs, the district court
3

Plaintiffs further argue that the balance of harms weighs in their favor,

reasoning that Denver “will endure little harm or hardship in complying with an

injunction” prohibiting a return to full-plane deicing at the gates because the injunction

would maintain the status quo. Aplt. Br. at 23. But because Plaintiffs have not

succeeded on the merits, we need not address this factor in assessing the propriety of

injunctive relief.

-11-

also erred in assuming that Denver would install fans in the ten mechanical

rooms. In Plaintiffs’ view, the court should have ensured rather than assumed

that Denver would not return to full-plane deicing at the gates and that it would

install the remaining fans.3

We are not persuaded. Our review of governing precedent persuades us

that the facts here do not show that the ADF at the Denver Airport “may present

an imminent and substantial endangerment to health.” 42 U.S.C. § 6972(a)(1)(B). 

The leading case on the subject is the Supreme Court decision in Meghrig. The

issue in Meghrig was whether § 6972(a)(1)(B) provides a remedy to recover for

past cleanup costs. See 516 U.S. at 482. After KFC Western, Inc. paid to clean

up petroleum contamination on property previously owned by Alan and Margaret

Meghrig, it sought restitution from the Meghrigs. See id. The Court held that

RCRA’s citizen-suit provision does not provide a remedy for past contamination

that no longer poses a danger. See id. at 485–86. It reasoned that “[a]n

endangerment can only be imminent if it threatens to occur immediately.” Id. at

485 (internal quotation marks omitted). The language may present, it explained,

“implies that there must be a threat which is present now, although the impact of
-12-

the threat may not be felt until later.” Id. at 486 (internal quotation marks

omitted). 

We followed Meghrig in Burlington Northern. Burlington Northern alleged

that the defendant’s earth-moving construction on his property had caused tar-like

material (TLM) to migrate onto Burlington Northern’s property. See 505 F.3d at

1018. Burlington Northern removed the TLM from its property and constructed a

berm on the property line to prevent future migration. See id. The district court

granted summary judgment against Burlington Northern, ruling that it “had failed

to present a genuine issue of material fact on the ‘imminent and substantial

endangerment’ element of its RCRA claim.” Id. (quoting § 6972(a)(1)(B)). The

court concluded that 

imminency had not been established because (1) [Burlington

Northern] failed to point to any person who had been injured by TLM

or to any study establishing the material threatened to ‘immediately’

cause harm to a person or the environment, (2) neither the

[Oklahoma Department of Environmental Quality] or the

Environmental Protection Agency . . . had ever ordered the TLM

removed, and (3) [Burlington Northern] monitored the alleged

migration of the TLM onto its property for years without acting.

Id. at 1021. 

We disagreed with the district court’s analysis, stating that it was

“irrelevant when the TLM was deposited on the property and equally irrelevant

how long [Burlington Northern] monitored the TLM before acting.” Id. We also

stated that the focus should have been on the risk that harm would occur in the
-13-

future, not on whether harm had occurred or was imminent. See id. We

explained the meanings of the statutory terms: “[A] finding of ‘imminency,’” we

said, “does not require a showing that actual harm will occur immediately as long

as the risk of threatened harm is present.” Id. at 1020. And we stated that “the

term ‘endangerment’ . . . mean[s] a threatened or potential harm,” id., and that an

endangerment is substantial when “there is reasonable cause for concern that

someone or something may be exposed to risk of harm by release, or threatened

release, of hazardous substances in the event remedial action is not taken,” id. at

1021. Thus, the statutory requirement could be satisfied even if the actual harm

might not be likely to occur for a long time, so long as the defendant’s current or

past actions create a present risk that the harm will eventually come to pass. See

id. at 1020–21. We emphasized “that the operative word in § 6972(a)(1)(B) is

‘may’”; a plaintiff need show only that the waste may present a threat of serious

potential harm. Id. at 1020. Noting the evidence in the record that TLM

contained carcinogens at levels exceeding EPA recommendations and that it

threatened storm-water runoff and other waters, we reversed and remanded for

further proceedings. See id. at 1022. 

Most recently, in Tyson Foods we considered the same statutory language

in reviewing whether the Oklahoma Attorney General was entitled to a

preliminary injunction against Tyson’s use of “‘poultry litter’” (which includes

poultry bedding materials and feces) as fertilizer in the Illinois River Watershed
-14-

(IRW). See 565 F.3d at 773–74. The state contended that bacteria in the poultry

litter was contaminating the watershed. Id. at 774. Tyson responded that the

bacteria in the IRW came from other sources and that the processing of poultry

litter kills the bacteria before the litter is spread on land. Id. We agreed with the

state that “under RCRA a plaintiff need not ‘show proof of actual harm to health

or the environment’ to establish endangerment, but rather injunctive relief is

appropriate where there simply may be a risk of harm.” Id. at 777 (quoting

Burlington Northern, 505 F.3d at 1020). Nevertheless, we concluded that

“Oklahoma’s inability to link land-applied poultry litter to the bacteria in the IRW

preclude[d] a finding that such litter may present an imminent and substantial

endangerment . . . .” Id. at 778. Consequently, the state had failed to show that

the litter “may be a risk of harm in the IRW waterways.” Id. at 777.

The above cases did not have occasion to explore every context in which a

solid waste “may present an imminent and substantial endangerment to health or

the environment.” But they do provide guidance. In particular, they illustrate

that there is a limit to how far the tentativeness of the word may can carry a

plaintiff. Meghrig tells us that an endangerment cannot be merely possible, but

must “threaten[] to occur immediately.” 516 U.S. at 485 (internal quotation

marks omitted). And although Burlington Northern recognizes that the harm may

not occur for a long time, see 505 F.3d at 1020–21, Tyson Foods emphasizes that
-15-

there is no endangerment unless the present or imminent situation can be shown

to present a risk of (later) harm, see 565 F.3d at 777. 

One essential point that Plaintiffs appear to overlook is that although the

harm may be well in the future, the endangerment must be imminent. See

Meghrig, 516 U.S. at 486 (“[T]here must be a threat which is present now,

although the impact of the threat may not be felt until later.” (internal quotation

marks omitted)). Two examples may clarify the difference between harm and

endangerment in the context of future harm. First, it may take a long time for a

toxic substance from the solid waste to reach the object to be harmed. For

instance, buried solid waste may present an endangerment if toxic chemicals from

the waste will eventually seep into the water table and be consumed by humans. 

No harm will result for years, but the endangerment already exists because that

harm can result if “remedial action is not taken” in the interim. Burlington

Northern, 505 F.3d at 1021; see Cox v. City of Dallas, Tex., 256 F.3d 281, 301

(5th Cir. 2001) (“As the old waste decomposes, the cover soil can settle, ground

and surface water can become contaminated with leachate, and dangerous gases

can form and migrate underground. This meets the ‘may present an imminent and

substantial endangerment’ standard.” (footnote omitted) (quoting

§ 6972(a)(1)(B)); Dague v. City of Burlington, 935 F.2d 1343, 1356 (2d Cir.

1991) (similar), rev’d in part on attorney-fee issue, 505 U.S. 557 (1992). Second,

there may be a long period between the time that a toxic substance from the solid
-16-

waste reaches the object to be harmed and the time that the harm manifests itself,

as when the toxic substance eventually causes cancer. See Maine People’s

Alliance & Natural Res. Def. Council v. Mallinckrodt, Inc., 471 F.3d 277, 279 n.1

(1st Cir. 2006) (“[I]f there is a reasonable prospect that a carcinogen released into

the environment today may cause cancer twenty years hence, the threat is

near-term even though the perceived harm will only occur in the distant future.”). 

The essential point is that the solid waste presents an endangerment if harm may

result absent further remedial measures. 

It is here that the Plaintiffs’ case fails. The risk presented by ADF is that

human health can be injured if (1) sufficient quantities of ADF (2) degrade into

sufficient quantities of hydrogen-sulfide gas, (3) which enter an area where

humans are present. This risk, this endangerment, must be imminent for there to

be a claim under RCRA. See § 6972(a)(1)(B). At the time of trial, however,

there was no detectable hydrogen-sulfide gas in Concourse B, and no prospect of

there being such gas; the gas could be a problem only if full-plane deicing were to

be renewed at the concourse gates and the measures instituted by Denver were

then to prove ineffective in protecting people from the gas. Thus, not only was

there no imminent harm, but there was also no imminent endangerment. Nothing

going on at the airport at the time of trial, or expected in the immediate future,

would, even without remedial measures, present a prospect of harm to human

health. If nothing changed, there was simply no possibility of sufficient hydrogen
-17-

sulfide in Concourse B to injure human health. It is not enough under RCRA that

in the future someone may do something with solid waste that, absent protective

measures, can injure human health. See Meghrig, 516 U.S. at 485–86.

Plaintiffs’ appellate briefs argue that the district court applied the wrong

legal standard, requiring the imminence of actual harm, not merely imminent

endangerment. They note that the court stated that its “‘working definition of

“imminence” is that there must be a current risk that harm will result in the near

future.’” Aplt. Br. at 16. (quoting Bench Ruling at 41). We agree with Plaintiffs

that the district court misspoke on this occasion during the hour and a half that it

delivered its oral decision from the bench. But the error is immaterial in light of

the court’s factual findings. The court did not rely on the absence of imminent

harm. Rather, the basis of its ruling was that there was no evidence that under

current conditions at the Denver Airport there would be measurable (much less

harmful) levels of hydrogen sulfide in Concourse B. See Bench Ruling at 34

(finding that the evidence of current conditions did not establish the presence of

dangerous levels of hydrogen sulfide or ADF); id. at 42–43 (noting that even

assuming that significantly more ADF degraded in the basement of Concourse B,

“there is insufficient evidence to demonstrate how much hydrogen sulfide would

be produced” and whether it would “rise to the level of creating a health

hazard.”).
-18-

Plaintiffs also argue that Denver ceased full-plane deicing at the gates only

as a result of the present lawsuit and that it is free to renew the practice if they

are denied relief. But the district court found that such a change would not be

imminent. It said that the prospect of resumption was only speculative and that

the evidence did not establish that Denver would resume full-plane deicing upon

termination of this litigation. Moreover, the court found that the evidence did not

show that even such a resumption would present a substantial health risk.

Finally, Plaintiffs rely on mootness doctrine to support their claim of

imminence. They point out that Denver’s cessation of full-plane deicing at the

gate does not make this case moot, because such deicing may resume. See

Friends of the Earth, Inc. v. Laidlaw Envt’l Servs. (TOC), Inc., 528 U.S. 167, 189

(2000) (“It is well settled that a defendant’s voluntary cessation of a challenged

practice does not deprive a federal court of its power to determine the legality of

the practice. If it did, the courts would be compelled to leave the defendant free

to return to his old ways. . . . The heavy burden of persuading the court that the

challenged conduct cannot reasonably be expected to start up again lies with the

party asserting mootness. ” (brackets, ellipsis, citations, and internal quotation

marks omitted)). But mootness doctrine is irrelevant to the RCRA requirements

at issue in this case. The district court did not dismiss the suit on jurisdictional

grounds (mootness), but because of Plaintiffs’ failure to prove their claim. A

RCRA suit cannot be brought because someone may sometime begin disposing of
-19-

solid waste in a manner that presents an endangerment. The endangering

practice—here, the resumption of gate deicing—must be imminent. See 42 U.S.C.

§ 6972(a)(1)(B). Plaintiffs’ suit was properly dismissed because the evidence

showed that resumption of full-plane gate deicing at Concourse B was not

imminent, but merely speculative. If the district court had been persuaded by the

evidence that Denver would likely resume full-plane deicing at the gates upon

conclusion of this litigation and that such a practice may present an imminent and

substantial endangerment to health, we presume that it could properly issue an

injunction under RCRA. That, however, is not the case we have before us. 

III. CONCLUSION

We AFFIRM the judgment of the district court.